820

Study of the Hygienic Quality, Physico-Chemical and Biochemical of Dried

Dates "Degla-Baidha" For Obtaining the Vinegar Through the Application

of Industrial Methods

Mme DEFFAIRI D1. AMIRI S. RABHALLAH M.

1 : Chargée de cours (MAA) – Département de biologie Faculté des Sciences Agrovétérinaires et Biologiques

université SAAD DAHLEB DE BLIDA ALGERIE

Mail : tahadjam@yahoo.fr

Abstract

Production dates ranks important in agriculture Algerian part of it remains unreleased (scrap).

To find a more lucrative market, we have proposed the valuation dates of low-value by the utilization

of biotechnological products to obtain new business easily and with high added value.

For this purpose, we have tried to make vinegar from date juice, variety "Degla Baidha" by the

application of industrial methods (fermentation)

The results have revealed:

-The morphological, physico-chemical, biochemical and microbiological study of dates are

acceptable.

-The good evolution of the alcoholic fermentation of juice of dates, due to the good growth of the

yeast Saccharomyces cerevisiae in this environment.

-The evolution of acetic fermentation is slow and complex due to the sensitivity of acetic acid bacteria

Acetobacter acetic.

-The analysis and the test carried out on tasting the vinegar obtained give very encouraging results.

In the light of this work we found that the use of this biotechnology allows one hand to produce

organic vinegar excellent nutritional value and other stimulating recovery from varieties of common

dates.

Keywords: Date-Baidha Degla,, extraction, fermentation, juice Dates, Valuation Vinegar.

1 Introduction

The Sahara is 90% of the area of Algeria, more than 2 million km2. The date palm (Phoenix

dactylifera.) Is a tree of great ecological and economic importance etsocio in the oasis of the

desert (El Hadrami et al., 2005). In consequence, it is the focus of agriculture and provides the

main resource of Financial oasis. Indeed, dates accounted for both human an animal

providential fruit alimentation. Their success over a long period can be explained by the

nutritional qualities of these particular fruits rich in sugars and enMinéraux (Benchelah and

Maka, 2008).

Note that, Algeria, with a production of 6,439,670 quintals (Anonymous 2010a) of dates has

not to our knowledge no processing technology dates to the exception of pulp "Ghars" from

soft dates the same name.

821

Agricultural and agro-industrial activities generate large amounts of waste that can provide

new materials for Many food industries. To this end, their valuations by biotechnological

processes represent a solution of choice to the extent that it can produce substances with high

added value and finally contributes to industrial and agricultural development of the country

(Acouren et al., 2008)

Dates low value can be used as substrates carbonésPar microbial species (yeast, bacteria, ...

etc..) To produce biomass. LesLevures are the first micro-organisms have been observed

under the microscope by Leeuwenhoek AntoineVan that drew them to 1680. They are a

valuable source deproteinized because they are home to a very active protein biosynthesis.

Many substances that we use every day are the result of the exploitation of microorganisms

whose origin dates back to the earliest times, but it was not until Pasteur's discoveries to be

able to establish the precise science that led to the birth of a fermentation industry outside the

traditional framework (bread, fermented beverages ... etc).. (Bacha, 2008)

Our work is in this perspective and focuses on the valuation date of a low value which is

Degla-Baidha dry variety trials by obtaining optimization vinegar and comparing it to that

made in " SIDNA "national facility for the production of vinegar.

2-MATERIALS AND METHODS

2.1. Plant Equipment

The plant material used is the dry variety Dagla-Baidha. Choice of this variety is justified by

its abundance in Algeria, sugar concentration content and facilitates conservation.

Fig1: the "Degla-Baidha" variety (Hannachi et al., 1998)

2.2. Biological Equipment

822

The biological material used for the production of alcohol is Saccharomyces cerevisiae. And

for the conversion of alcohol into acetic acid acètiè Acetobacter strain is isolated from

acetator Frings

3- Experimental Protocol

3.1. juice preparation date:

Once washed dates, pitted and crushed. 2.5 liters of water is added to 1 kg of dates. Heated in

a water bath at 85 ° C for 45 minutes and with continuous stirring. The must obtained is

filtered through a filter and then sterilized in an autoclave at 120 ° C for 20 minutes.

Fig2 :juice date

Table 1: Characteristics of date juice obtained

Parameter Value

823

2-The fermentation

2.1. Preparation of Wort To ensure the smooth running of the alcoholic fermentation, the juice of dates undergo some operations shown

in Figure 10.

Décongélation

Fig3 :Steps in preparing wort fermentation (Acourène et al, 2008.e et al.,2008)

2.2. Implementation of the Alcoholic Fermentation

This operation aims to grow the yeast Saccharomyces cereviciea in date juice and give a greater amount of

biomass

The different stages of fermentation are shown in figure11.

-The start of the alcoholic fermentation occurs by the release of CO2.

-The parameters analyzed during this process are:

* The pH. * The ° Brix. * The alcohol content.

The stop-release of CO2 indicates the end of the fermentation cycle.

Using Ebulliometer as rapid method for the measurement of Alcoholic degree:

pH

IR

IB (DO à 420 nm)

Brix (%)

5,90

1, 365

0,6

14,5

Décongélation

Ajustement de pH à 4,5 par le jus de citron

Stérilisation à 120°C pendant 15 min à l’autoclave

Jus de dattes stérilisé (le moût)

824

Definition: Ebulliometer probe electronic-Ref, 160350D: Is a hydrometer used as a simple and rapid method for

the determination

the alcohol content of wine. (see fig 6).

ulliomèter on the disk, read in front of the boiling temperature Tvin alcohol content of wine.

example:

Tvin = 91.4 ° C, as wine disk = 1

Fig6: Ebulliometer with e-Réf.160350D probe.

2.2.Kinetics of alcoholic fermentation

The following during alcoholic fermentation parameters: pH, brix level, alcohol

2.2. Evolution of pH During the Fermentation (Figure 16)

825

0

0,5

1

1,5

2

2,5

3

3,5

4

4,5

5

0 heures 24 heures 48 heures 72 heurestime(houres)

P H

p H

Fig 7: Evolution of pH during the fermentation

According to the curve shows that the pH of the juice decreases or during fermentation to reach a value of 3.6 in

24 hours then a slight increase in pH

According to Akin (2008), who modeled the variation of pH during the fermentation of grape juice, pH

decreases hang early in the process as a result of production of acidic compounds (succinic acid, lactic acid,

acetic ...) by yeast and mainly due to an increase in the production of ethanol which changes the dissociation

constant of the components and especially organic acids.

II-2-2-Evolution of alcohol content during alcoholic fermentation

Follow the evolution of alcohol content is through the use of ebulliometer.

The alcohol level obtained is 8.6 alcohol level after 72heurs and this value indicates the smooth running of the

alcoholic fermentation (figure 17).

According Boukhiar, 2009L'alcool is the major compound produced during alcoholic fermentation. Through

known literature that alcohol affects the refractive index, density, and thus the dissociation constants of the acid

compounds of the solvent.

826

0

1

2

3

4

5

6

7

8

9

10

0 heures 24 heures 48 heures 72 heures

Alcool

Alcool

TIME

Figure8: Evolution of alcohol during fermentation

2.2.3. Evolution of Brix During Alcoholic Fermentation

We see from Fig (18) that (Rate soluble solid) decreases during the fermentation jusqu'la value of 6 and the

decrease can be interpreted by the transformation of sugar into ethanol by yeast Saccharomyces cereviciae.

0

2

4

6

8

10

12

14

16

0 heures 24 heures 48 heures 72 huresTIME

°Brix

Fig9: Evolution of brix during alcoholic fermentation

2.3. Analysis of Fermented Date Juice

The product obtained was characterized by: (pH = 4, 3), (brix = 6), (alcohol content = 8.6)

827

¶

Fig 10: date juice fermented (wine dates)

The 3-acetic fermentation

A-method of manufacturing vinegar at the factory SINPAC

The manufacturing process of vinegar applied in this property is based on the cycle of Fed-batch

fermentation for the production of vinegar concentration proposed by (Park et al., 1991).

1. Preparation tank wort:

-The wort is a mixture of alcohol, vinegar, and nutrients (BionylF15).

BionylF15: specific nutrient for lactic acid bacteria in the form of a powder (sugars, mineral salts and yeast

extract), it should be dissolved in a small vessel before mixing vinegar with must

. To 1000 l of wort, add about 2.5 kg of nutrient.

The uniform-composition of wort: 1.2-1.5% acid and 11.3% alcohol.

2. The Acétator Frings = the fermenter (see Figure 13)

-The tank of Acétator a total capacity of about 16000l, during fermentation, it is filled with liquid 12000l.

-Always follow the two essential parameters (acidity and alcohol) to monitor the evolution of acetic

fermentation.

-When, during the fermentation, the residual alcohol content reached 0.3-0.4 must extract and vinegar 5600L

5600L automatically load mout, so Acétator still contains vinegar, called "mother vinegar "for the survival of

acetic acid bacteria. The refrigeration-is by means of a coolant, wherein the cooling water flows, the aeration is

performed by turning immediately above the bottom of the aeration tank, the two operations are controlled

automatically.

3. Drain tank 4.Unité of 5.Cuve filtration storage filtered vinegar

6. Dilution tank for setting the level of marketing:. Vinegar withdrawn at an acidity of 8.5% Next legislation

vinegar sold in bottles containing an acidity of 5%, so there is a process of dilution with drinking water.

828

Fig 11: Acétator of frings (Bourgeois and Larpent, 1996)

B-The realization of the acetic fermentation of wine dates according to industrial methods

The production of large quantities of vinegar requires continuous addition of date wine vinegar in a mode of

aerobic fermentation. Ainsi1, 2 liters of alcohol dates we add two quarts of vinegar in a certification every 36

hours, a quantity of vinegar is withdrawn either 500ml or 1 liter and add the same amount of alcohol dates.

(Boughnou 1988).

1. Preparation must: the must of our work is the fermented juice of dates with an alcohol content of 8.6% and

1.5% acidity. First, the juice should be thawed and clarified, then added a small amount of nutrient Bionyl F15

(2.5 g / 1l wort).

2. The implementation of the acetic fermentation

-It takes 250ml of wort in a beaker and 250 ml of vinegar mother recovered from the Acétator Frings at the time

close to the end of the fermentation cycle, where the bacterial population is more dense, with about 8.5% acidity

of less than 0.5% and the alcohol content.

-After stirring thoroughly, the mixture is divided into three erlennmeyrs.

The erlennmeyrs they let in a marine bath aerobically at a temperature of 30 ° C for 7 days, during which each

time we checked the two essential parameters (acidity and alcohol content), knowing that at the beginning of the

fermentation acetic acid the mixture of 4.3% acidity and 3.6% alcohol content.

4-Sensory analyzes

It is a hedonic evaluation performed according to the protocol described in the Standards (AFNOR, 1975)

The sample is presented to the tasters (n = 10) so modanique (one sample) and the subject must express its

opinion on the flavor (nice) on a rating scale to 6 points

6. Very nice

5. rather nice

4. Neither pleasant nor unpleasant

3. Uncongenial

2. Rather unpleasant

1. Disagreeable

3. Results and interpretation of acetic fermentation

After 7 days of acetic fermentation yields a finished product characterized by three main parameters (alcohol

content = 1.2. Brix = 4.5%. And acidity = 5.3%), see Figure

829

Fig 12: finished product obtained

As explained, it starts with a wort fermentation characterized by (alcoholic = 3.6 degree and acidity = 4.3),

despite the acetic fermentation was lasted 7 days, but we have not reached the acetify wort fermentation mainly

alcohol

Accordance with approved standards (alcohol does not exceed 0.5% (JORA, 1998), the major drawback lies in

the acetic acid bacteria, it is true that after 7 days the acidity reaches 5, 5% indicates the conversion acetic acid in

alcohol, but the decrease of alcohol 1,2 alcoholic degree not only due to the transformation of the alcohol into

acetic acid

but also about the possible breakdown of alcohol during acetic fermentation because it is an aerobic fermentation

thus reduces the yield of acetic acid.

Indeed, the difficulty of mastering this bioconversion, ethanol acid

acetic acid, may explain this result, the industry vinegar uses stem not from pure cultures in industrial conditions,

the selection pressure is high and the emergence of low-performing variants is limited since the fermentations

were be conducted hang several years without loss of activity and performance. (Bourgeois and Larpent, 1996).

Product comparison from the industrial vinegar SINPAC

This comparison is made on the following indices: alcohol, brix content and acidity.

830

Fig13: Industrial vinegar and vinegar obtained

Table 2: Comparison of vinegar

III-Sensory analysis (AFNOR, 1975)

Analyses of sensory organs comparing two products are shown in the table below.

sample

Attribute A

Industrial vinegar B

Vinegar-based date

Transparent yellow color turns brown

Very hot pungent odor

Rather nice pleasant flavor

Rather acid acid acid

The results obtained for the product (vinegar base date) for flavor are as follows:

6. Very pleasant 1dégustateur

5. rather pleasant: 5 tasters

4. Neither pleasant nor unpleasant: 3 tasters

3. Unpleasant: 1

2. Rather unpleasant: 0

1. Unpleasant: 0

Table XIII: Comparison of the two samples (sensory analysis)

I-Sensory analysis (AFNOR, 1975)

Analyses of sensory organs comparing two products are shown in the table below.

The results obtained for the product (vinegar base date) for flavor are as follows:

Vinaigre industrielle Vinaigre obtenue

Le degré brix :5% 4,5%

Teneur d’alcool : 0,3°GL 1,2°GL

L’acidité : 8,5% 5 ,3%

831

6. Very pleasant 1dégustateur

5. rather pleasant: 5 tasters

4. Neither pleasant nor unpleasant: 3 tasters

3. Unpleasant: 1

2. Rather unpleasant: 0

1. Unpleasant: 0

Table XIII: Comparison of the two samples (sensory analysis)

Les résultats obtenus pour le produit (vinaigre à base de datte) pour la saveur sont comme suit :

6. Très agréable : 1dégustateur

5. plutôt agréable : 5 dégustateurs

4. Ni agréable, ni désagréable : 3 dégustateurs

3. Peu agréable : 1

2. Plutôt désagréable :0

1. Désagréable : 0

Tableau XIII : comparaison des les deux échantillons (Analyses sensorielles)

Les résultats sont représentés sous forme d’histogramme statistique (figure 14).

Fig 14: graphic histogram sensory analysis (flavor)

From the results we can

say that the value 5 (rather

nice) of the rating scale is

the value that represents the

Echantillon

Attribut

A

Vinaigre industriel

B

Vinaigre à base de

datte

Couleur transparent Jaune vire au brun

Odeur Très piquant piquant

Saveur agréable Plutôt agréable

Acidité Plutôt acide Acide

832

acceptable score and indicates that our product to an acceptable value according to the rating scale.

Conclusion

Using dates of low market value as a substrate for their development by biotechnological routes currently

interested in research in order to obtain consumable products with high added value. For this reason, we try to

produce vinegar from date juice, variety "Degla-Baidha" and the determination of some of its features.

The most interesting at the end results of this work are:

-The physical analysis of the date "Degla-Baidha" shows that it is very acceptable physical characteristics (with a

weight of 6.29 g where the pulp is more than 80%, a length of 3.65 cm and a width of 1.70 cm).

-The physico-chemical analysis shows the consistency of the dry variety (14.53% moisture) to facilitate its

conservation.

-From a microbiological point, this variety has a very good microbiological quality, so a treatment specific

storage is not necessary.

-The biochemical analysis showed its high fermentable sugars (reducing sugars 46%), these sugars are used as

organic substrate for the production of biomass. The juice of dates obtained with 14.5 ° brix is a favorable

environment for the conduct of the alcoholic fermentation.

-The fermentation carried out on the date juice gives a good yield of alcohol (8.6 ° GL), which shows good

growth of yeast Saccharomyces cerevisiae in this environment.

-The results of the acetic fermentation show the conversion of a certain quantity of wine dates to acetic acid, but

this operation is slow and complex because of the sensitivity of acetic acid bacteria Acetobacter vis-à-vis the

various environmental factors.

-Vinegar obtained (1.2 ° GL alcohol) is not consistent with Algerian law (0.5 ° GL alcohol), but the taste test

this is very encouraging results.

In the light of these results, some recommendations are necessary:

-Production of acetic fermentation of the juice fermented dates in the best conditions that need acetic bacteria

and follow its evolution and analyze vinegar obtained.

-The study of structural and functional characteristics of acetic acid bacteria in particular the genus Acetobacter

acetic.

-Determination of minor compounds of date "Degla Baidha" (vitamins, minerals, amino acids ....).

-The study of the morphological and biochemical characteristics of this core to introduce variety in the

valuation process.

-The study of the nutritional value of vinegar dates.

-Evaluation of the economic interest of the development of dry by the production of alcohol, vinegar and

dates.

Finally, we hope this study an application on an industrial scale to achieve the production and marketing of

legitimate date vinegar, and give the dates of low value high added value.

Références bibliographiques :

833

[1] El Hadrami, A., El Idriss, T., El Hassni, M., Daayf, F., El Hadrami, I., 2005. Toxin-based

invitroselection and its potential application to date palm for resistance to the bayoud Fusarium wilt. C.

R. Biologie 328, pp. 732-744

[2] Benchelah, A.-C. , Maka, M., 2008. Les Dattes, intérêt et nutrition.

Phytothérapi (ethnobotanique) Springer, vol N°6, pp. 117 -121.

[3] Anonyme,2010. Statistiques agricoles superficies et productions. Ministère de l'Agriculture etdu

développement rural, Série A palmiers dattier, pp.

[4] Acourene,S. ,Ammouche,A.,Djaarfi,K.,2008.Valorisation des rebuts de dattes par la production de

la levure boulangere, de l’alcool et de vinaigre ,pp.39-45

[5] Bacha,A.,2008.Production et étude de l’activité de l’invertase produite par le levure Saccharomyces

cerevisiae sur substrat à base de datte. Thèse Magister, BATNA

[6] Hannachi,S.,Khitri,D.,Benkhalifa,A.,Brac de Perrière R.A.,1998. Inventaire variétal de

palmeraie algérienne.225p.

[7] Touzi, A., 1997. Valorisation des produits et sous-produits de la datte par les procédés

biotechnologiques. Rapport de synthèse de l’atelier “Technologie et qualité de la datte”, CIHEAM -

Options Méditerranéennes, pp. 214

[8] Boukhier, A.,2009. Analyse de processus traditionnel d’obtention du vinaigre de datte tel

qu’appliqué au sud Algérien : essai d’optimisation .thèse magistère option : technologie alimentaire,

Boumerdes

[9] Akin, H., 2008. Evolution du pH pendant la fermentation alcoolique de moûts de raisins :

[10] Park ,YS.,Toda,K., Fukaya ,M.,Okumura,H.,Kawamura ,Y.,1991.Production of a high

concentration acetic acid by Acetobacter aceti using a repeated fed-batch culture with cell

recycling.Appl.microbiol.Biotech.35 :pp.149-153.

[11] Bourgeois, C.M., Larpent, J.-P., 1996. Microbiologie Alimentaire : aliments fermentés et

fermentations alimentaires (Tome 2). Edition Techniques et documentations, 623 p

[12] Boughnou, N., 1988. Essai de production du vinaigre à partir des déchets de dattes . Thèse

Magister INA El-Harrach, 82 p.

[13] AFNOR organisation française de normes des produits dérivés des fruits et légumes

jus de fruits. Ed. AFNOR, 325 p.

[14] Journal Officiel de la République Algérienne 29-Mars 1998. « Arrêté sur le vinaigre ».Vol

18N°17.

Echantillon

Attribut

A

Vinaigre industriel

B

Vinaigre à base de

datte

Couleur transparent Jaune vire au brun

Odeur Très piquant piquant

Saveur agréable Plutôt agréable

Acidité Plutôt acide Acide